1. FIELD OF THE INVENTION
The invention relates to a controller which is able, through the medium of an automatic billing system whereby a user can be billed for a composite charge made up of the combined total of a call charge and a special utilization charge, to issue a bill for an invoice charge which has arisen despite the fact that the user has not made use of a telephone line.
2. DESCRIPTION OF THE PRIOR ART
There are known automatic billing systems which function in such a way that if, for example, an information provision device, which has been installed on the premises of an information provider and listed as a special line number, is called up by a user and information subsequently obtained from said information provision device by way of a telephone line, a utilization charge computation means, which has been installed in a telephone exchange which stands between the information provider and the user, counts the number of seconds during which the user is connected with the information provider in order to compute a utilization charge which is then added by the telephone company to the user's call charge and the resultant composite charge ultimately collected from the user. The use of this sort of automatic billing system enables the telephone company to collect the utilization charge on behalf of the information provider and this in turn relieves the information provider of the burden of carrying out his own bill collection work. In this sort of case, however, the system can only be used for the computation of a utilization charge in cases where the user has obtained his service by way of a telephone line and it is not, therefore, available for the billing of invoice charges which have arisen in some other way. For example, if a user becomes liable to a charge which has arisen through his use of some sort of service which has not required the intermediation of a telephone line, the telephone company's utilization charge computation means will not be called into operation with the result that the supplier of the service cannot make use of the aforementioned automatic billing system as a means of collecting the resultant charge.